postgres

Commit Graph

Author	SHA1	Message	Date
Amit Kapila	ddd5f4f54a	Add a slot synchronization function. This commit introduces a new SQL function pg_sync_replication_slots() which is used to synchronize the logical replication slots from the primary server to the physical standby so that logical replication can be resumed after a failover or planned switchover. A new 'synced' flag is introduced in pg_replication_slots view, indicating whether the slot has been synchronized from the primary server. On a standby, synced slots cannot be dropped or consumed, and any attempt to perform logical decoding on them will result in an error. The logical replication slots on the primary can be synchronized to the hot standby by using the 'failover' parameter of pg-create-logical-replication-slot(), or by using the 'failover' option of CREATE SUBSCRIPTION during slot creation, and then calling pg_sync_replication_slots() on standby. For the synchronization to work, it is mandatory to have a physical replication slot between the primary and the standby aka 'primary_slot_name' should be configured on the standby, and 'hot_standby_feedback' must be enabled on the standby. It is also necessary to specify a valid 'dbname' in the 'primary_conninfo'. If a logical slot is invalidated on the primary, then that slot on the standby is also invalidated. If a logical slot on the primary is valid but is invalidated on the standby, then that slot is dropped but will be recreated on the standby in the next pg_sync_replication_slots() call provided the slot still exists on the primary server. It is okay to recreate such slots as long as these are not consumable on standby (which is the case currently). This situation may occur due to the following reasons: - The 'max_slot_wal_keep_size' on the standby is insufficient to retain WAL records from the restart_lsn of the slot. - 'primary_slot_name' is temporarily reset to null and the physical slot is removed. The slot synchronization status on the standby can be monitored using the 'synced' column of pg_replication_slots view. A functionality to automatically synchronize slots by a background worker and allow logical walsenders to wait for the physical will be done in subsequent commits. Author: Hou Zhijie, Shveta Malik, Ajin Cherian based on an earlier version by Peter Eisentraut Reviewed-by: Masahiko Sawada, Bertrand Drouvot, Peter Smith, Dilip Kumar, Nisha Moond, Kuroda Hayato, Amit Kapila Discussion: https://postgr.es/m/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com	2 years ago
Amit Kapila	c393308b69	Allow to enable failover property for replication slots via SQL API. This commit adds the failover property to the replication slot. The failover property indicates whether the slot will be synced to the standby servers, enabling the resumption of corresponding logical replication after failover. But note that this commit does not yet include the capability to sync the replication slot; the subsequent commits will add that capability. A new optional parameter 'failover' is added to the pg_create_logical_replication_slot() function. We will also enable to set 'failover' option for slots via the subscription commands in the subsequent commits. The value of the 'failover' flag is displayed as part of pg_replication_slots view. Author: Hou Zhijie, Shveta Malik, Ajin Cherian Reviewed-by: Peter Smith, Bertrand Drouvot, Dilip Kumar, Masahiko Sawada, Nisha Moond, Kuroda, Hayato, Amit Kapila Discussion: https://postgr.es/m/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com	2 years ago
Tomas Vondra	2c7ea57e56	Revert "Logical decoding of sequences" This reverts a sequence of commits, implementing features related to logical decoding and replication of sequences: - `0da92dc530` - `80901b3291` - `b779d7d8fd` - `d5ed9da41d` - `a180c2b34d` - `75b1521dae` - `2d2232933b` - `002c9dd97a` - `05843b1aa4` The implementation has issues, mostly due to combining transactional and non-transactional behavior of sequences. It's not clear how this could be fixed, but it'll require reworking significant part of the patch. Discussion: https://postgr.es/m/95345a19-d508-63d1-860a-f5c2f41e8d40@enterprisedb.com	4 years ago
Tomas Vondra	a180c2b34d	Stabilize test_decoding touching with sequences Some of the test_decoding regression tests are unstable due to modifying a sequence. The first increment of a sequence after a checkpoint is always logged (and thus decoded), which makes the output unpredictable. The runs are usually much shorter than a checkpoint internal, so these failures are rare, but we've seen a couple of them on animals that are either slow or are running with valgrind/clobber cache/... Fixed by skipping sequence decoding in most tests, with the exception of the test aimed at testing decoding of sequences. Reported-by: Amita Kapila Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com	4 years ago
Tomas Vondra	80901b3291	Add decoding of sequences to test_decoding Commit `0da92dc530` improved the logical decoding infrastructure to handle sequences, and did various changes to related parts (WAL logging etc.). But it did not include any implementation of the new callbacks added to OutputPluginCallbacks. This extends test_decoding with two callbacks to decode sequences. The decoding of sequences may be disabled using 'include-sequences', a new option of the output plugin. Author: Tomas Vondra, Cary Huang Reviewed-by: Peter Eisentraut, Hannu Krosing, Andres Freund Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca	4 years ago
Michael Paquier	1922d7c6e1	Add SQL functions to monitor the directory contents of replication slots This commit adds a set of functions able to look at the contents of various paths related to replication slots: - pg_ls_logicalsnapdir, for pg_logical/snapshots/ - pg_ls_logicalmapdir, for pg_logical/mappings/ - pg_ls_replslotdir, for pg_replslot/<slot_name>/ These are intended to be used by monitoring tools. Unlike pg_ls_dir(), execution permission can be granted to non-superusers. Roles members of pg_monitor gain have access to those functions. Bump catalog version. Author: Bharath Rupireddy Reviewed-by: Nathan Bossart, Justin Pryzby Discussion: https://postgr.es/m/CALj2ACWsfizZjMN6bzzdxOk1ADQQeSw8HhEjhmVXn_Pu+7VzLw@mail.gmail.com	4 years ago
Alvaro Herrera	9f06d79ef8	Add facility to copy replication slots This allows the user to create duplicates of existing replication slots, either logical or physical, and even changing properties such as whether they are temporary or the output plugin used. There are multiple uses for this, such as initializing multiple replicas using the slot for one base backup; when doing investigation of logical replication issues; and to select a different output plugins. Author: Masahiko Sawada Reviewed-by: Michael Paquier, Andres Freund, Petr Jelinek Discussion: https://postgr.es/m/CAD21AoAm7XX8y_tOPP6j4Nzzch12FvA1wPqiO690RCk+uYVstg@mail.gmail.com	7 years ago
Alvaro Herrera	c40489e449	Fix logical replication slot initialization This was broken in commit `9c7d06d606`, which inadvertently gave the wrong value to fast_forward in one StartupDecodingContext call. Fix by flipping the value. Add a test for the obvious error, namely trying to initialize a replication slot with an nonexistent output plugin. While at it, move the CreateDecodingContext call earlier, so that any errors are reported before sending the CopyBoth message. Author: Dave Cramer <davecramer@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CADK3HHLVkeRe1v4P02-5hj55H3_yJg3AEtpXyEY5T3wuzO2jSg@mail.gmail.com	8 years ago
Michael Paquier	56a7147213	Block replication slot advance for these not yet reserving WAL Such replication slots are physical slots freshly created without WAL being reserved, which is the default behavior, which have not been used yet as WAL consumption resources to retain WAL. This prevents advancing a slot to a position older than any WAL available, which could falsify calculations for WAL segment recycling. This also cleans up a bit the code, as ReplicationSlotRelease() would be called on ERROR, and improves error messages. Reported-by: Kyotaro Horiguchi Author: Michael Paquier Reviewed-by: Andres Freund, Álvaro Herrera, Kyotaro Horiguchi Discussion: https://postgr.es/m/20180626071305.GH31353@paquier.xyz	8 years ago
Simon Riggs	9c7d06d606	Ability to advance replication slots Ability to advance both physical and logical replication slots using a new user function pg_replication_slot_advance(). For logical advance that means records are consumed as fast as possible and changes are not given to output plugin for sending. Makes 2nd phase (after we reached SNAPBUILD_FULL_SNAPSHOT) of replication slot creation faster, especially when there are big transactions as the reorder buffer does not have to deal with data changes and does not have to spill to disk. Author: Petr Jelinek Reviewed-by: Simon Riggs	8 years ago
Andres Freund	bae9b80160	Force synchronous commit in new-ish test_decoding test. This was missed in `a924c327` ff.	9 years ago
Peter Eisentraut	fdf71389dd	Various temporary slots test improvements Fix the tests on slow machines (per buildfarm). Add test for dropping on error. And also try to consume real changes from temporary slots. From: Petr Jelinek <petr.jelinek@2ndquadrant.com>	9 years ago
Tom Lane	23f722ba8e	Fix race condition in test_decoding "slot" test. This test, just added in commit `a924c327e`, sometimes fails because the old backend hasn't finished dropping the temporary replication slot when the new backend looks. Borrow the previously-invented methodology for waiting for the old process to disappear from pg_stat_activity. Petr Jelinek Discussion: https://postgr.es/m/62935e6f-4f1b-c433-e0fa-7f936a38b3e5@2ndquadrant.com	9 years ago
Peter Eisentraut	a924c327e2	Add support for temporary replication slots This allows creating temporary replication slots that are removed automatically at the end of the session or on error. From: Petr Jelinek <petr.jelinek@2ndquadrant.com>	9 years ago

14 Commits (758479213d574d6e2fbbdfee5328edef3d60da61)